AuthorizationUnsuccessful error about xeroizer HOT 2 CLOSED

require 'active_support/isolated_execution_state' # https://github.com/waynerobinson/xeroizer/issues/555
require 'sinatra'
require 'xeroizer'

# Get these parameters at https://developer.xero.com/app/manage/
#
XERO_CLIENT_ID = "xxx"
XERO_SECRET = "xxx"

# https://developer.xero.com/documentation/oauth2/scopes
# N.B. must have offline_access for token refresh to work
XERO_SCOPE = %w(
    accounting.settings.read
    accounting.transactions
    accounting.contacts.read
    offline_access
).
join(" ")

# Make sure this matches the "Redirect URI" - can be localhost for testing!
#
XERO_REDIRECT="http://localhost:3000/redirect"

# Generate this with e.g. openssl rand -base64 30
SESSION_SECRET="xxx"

configure do
    enable :sessions
    set :session_secret, SESSION_SECRET
end

helpers do
    def save_xero_to_session
        session[:xero][:access_token] = @xero.access_token.token
        session[:xero][:refresh_token] = @xero.access_token.refresh_token
        session[:xero][:expires_at] = @xero.access_token.expires_at
        session[:xero][:tenant_id] = @xero.current_connections.first.tenant_id
    end

    def xero
        @xero = Xeroizer::OAuth2Application.new(
            XERO_CLIENT_ID,
            XERO_SECRET,
            session[:xero] ? {
                tenant_id: session[:xero][:tenant_id],
                access_token: session[:xero][:access_token],
                refresh_token: session[:xero][:refresh_token]
            } : {})
        if session[:xero] && Time.now+60 > Time.at(session[:xero][:expires_at])
            @xero.renew_access_token
            save_xero_to_session
        end
        @xero
    end
end

get '/login' do
    # Redirect user to Xero login page
    redirect xero.authorize_url(redirect_uri: XERO_REDIRECT, scope: XERO_SCOPE)
end

get '/redirect' do
    # Xero sends user back here once authenticated
    xero.authorize_from_code(params[:code], redirect_uri: XERO_REDIRECT)
    save_xero_to_session
    redirect '/invoices'
end

get '/invoices' do
    [200, {"content-type" => "text/plain"}, xero.Invoice.all(order: 'Date').inspect]
end